'Insects, Fires, and Climate Change: Implications for Snow Cover, Water Resources, and Ecosystem Recovery in Western North America'Paul Brooks (brooks@hwr.arizona.edu), University of Arizona

An extended period of snow cover is a dominant climatic characteristic of montane environments in western North America. Recent research has demonstrated that the water stored in this seasonal snow cover is the primary source not only of river discharge but also groundwater recharge and plant available water during the growing season. Although the recorded interannual variability of snow cover is quite large, ongoing changes in climate, combined with accelerating rates of forest disturbance from insects, fire, and drought, differentially are affecting the amount, timing, and partitioning of snow cover to an extent not captured in the instrumental record. A critical knowledge gap exists in predicting how these concurrent changes in climate and vegetation in topographical complex mountain environments will affect future water resources both for society and for terrestrial and aquatic ecosystems.
This presentation addresses that knowledge gap through a meta analysis recent work on snowpack dynamics, runoff generation, catchment biogeochemistry, and ecosystem productivity from seasonally snow-covered forests along a gradient of snow depth and duration in the Intermountain West. Observations include long-term SNOTEL monitoring stations, CZO, LTER, and USDA observations of landsurface-atmosphere water and carbon exchange, and post disturbance observations from recently burned forests, and areas of extensive insect-induced forest mortality. Together these observations can be used to identify landscapes most at risk to climate change as well as to develop management alternatives that minimize the effects of climate change on high elevation forests and the services of water provision and carbon storage they provide